Process for the production of carboxylic acids



Patented July 16, 1935 H 7 UNITED STATES PATENT. OFFICE Gilbert B. Carpenter, lsellemocr, Del, assignor to A E. I. du Pont de Nemours it Company, Wilmington, Del, a corporation of Delaware No Drawing. Application August 24, 1931, Serial No. 559,124 a 8 Claims. (Cl. 260-416) This invention relates to the synthesis of ortitanium, zirconium, and boron. 'I'heacidicox- 'ganic compounds and particularly to the preparaides may be employed unsupported or supported tion or" higher aliphatic acids by the interaction on the usual types of catalytic supports such,

7 of oleiines, carbon monoxide, and steam. for example, as charcoal, fullers earth, kiesel- Aliphatic acids of the higher order such as proguhr, etc. r I picnic acid, butyric acids, etc., have been here- Raw materials suitablefor use in the process tofore prepared by various methods. For exare readily available from a number of sources. ample, propionic acid has been obtained by the Thus, ethylene and various homologues thereof reduction of acrylic or lactic acid; by suitable Scln are found in the gases evolved in cracking'petrole 10 zomycetes fermentation of the lactate or malate um and may beseparated therefrom, for example, 10 of calcium; or by the oxidation of propyl alcohol by fractional liquefaction. It is preferable, for with dichromate solution. Such methods of prethe sake of avoiding undesirable by-products, paration are necessarily expensive due principally that the hydrocarbon which it is desired to conto the relatively high cost of the raw materials. vert be employed in a relatively high degree of Owing to the many important uses to which acids purity. r

or this type are adaptable, many of which uses The carbon monoxide required forthe synthesis have not been exploited extensively due to their, may conveniently be derived from various compresent high cost, it is obvious that a process for mercial sources, such as, for example, watertheir preparation from raw materials, which are, gas, producer gas, etc., by liquefaction orother at present, readily available and which will be methods and should likewise for thebest results 20 even more readily available in the near future, be relatively pure. V will be of far reaching importance in this art. Inert gases, such asnitrogen, may be included my copending application Ser. No. 559,130, with the reactants, this being advantageous'in a process is described for the preparation of all om cas fr m h s ndp int f ntr llin phatic carboxylic acids of the higher orderby the the temperature of the exothermic reaction and 25 reaction of steam, carbon monoxide, and an oleof limiting the extent thereof, where it mayflbe finic hydrocarbon, i. e. an aliphatic hydrocarbon desired to restrict the overall conversion of the containing a double bond,--ior example, the olereactants for the sake of enhancing the relative fines ethylene, propylene, butylene, etc.,the syny d of the desired acids.

0 thesis producing from these olefmes propionic, The relative proportions of the reactants can butyric, and valeric acids respectively. The acid be varied although it h be o d t at v y produced contains one more carbon atom than advantageous results are obtained when the steam the unsaturated hydrocarbon treated. and carbon monoxide are in excess with respect to A object, of th present in ention is to prothe olefinic hydrocarbon. Concentrations of the vide a process for the preparation of aliphatic latter within the range of from to 5% by 35 carboxylic acids from steam, carbon monoxide, volume of the total reactants have been emand olefinic hydrocarbons. A further object of p y W $0001 u tsthis invention is to provide a process for the The use of pressures in excess of atmospheric, preparation of monocarboxylic acids from steam, say from 25 to 900 atmospheres, is preferred.

carbon monoxide and an olefine in the presence The reaction proceeds over a wide range of tem- 40 of a catalyst. Another object of the invention peratures although the optimum temperature vais to provide a process for the preparation of acids ries with specific Cases, depending inter l a \IDOII having the structural formula RCHzCOOH from the hydrocarbon being used. Generally the desteam, carbon monoxide, and an olefinic hydro sired reaction can be obtained at from 200 to carbon, the R indicating a substituted or unsub- 400 C. From th standpoint of Drafitical p 45 stituted alkyl or aralkyl grouping. Other ob-' tion the temperature should not be so low that jects and advantages will hereinafter appear. the reaction rate is uneconomical nor so high as According to the present invention, aliphatic to result in undesirable by-products by decomcarboxylic acids are prepared from steam, carbon position and/or polymerization of raw materials.

monoxide, and an olefinic hydrocarbon by passing From this point of view the process has been 50 these materials in the vapor phase over a catalyst found to operate satisfactorily at from 275 to comprising one or more acidic oxides of Groups 375 C.

III, IV, V, and VI of the periodic table and par- The following examples will illustrate one ticularly the oxides of molybdenum, phosphorus, method of practising the invention, although the arsenic, tungsten, uranium, chromium, vanadium, invention is not limited to the examples.

. Upon condensation of the reaction product it was found that a good yield of aliphatic carboxylic acid containing a high percentage of propionic acid was obtained.

Example 2.The gaseous mixture described in Example 1 is passed over a molybdic oxide.-

yentional type and preferably one in 'which the temperature of exothermic reactions can be readlily controlled at the desiredvalue. Owing to the corrosive action of the acids produced, the interior ofithe converter and conduits leading therefrom; should preferably be protected. This may be accomplished by using glass or glass-lined apparatus or by coating the inner surfaces of the apparatus with chromium or silver or using for the construction of this equipment acid-resisting alloys of, for example, molybdenum, cobalt, tungsten, chromium, manganese, or nickel.

Various changes may be made in the method :hereinbefo-re described without departing from "the invention or sacrificing the advantages th reon.

I claim: s

1. In a process of reacting a gaseous mixture fcontaining. an olefinic hydrocarbon, carbon monoxide, and steam and thereby producing an aliphatic carboxylic acid the step of passing the gaseous mixture over a solid acidic oxide as a catalyst for the reaction;

2. In a process of reacting a gaseous mixture containing an olefine, carbon monoxide, and steam and thereby producing an aliphatic carboxylic acid the step of passing the gaseous mix- -ture over a solid acidic oxide as a catalyst for the reaction.

3. In a process of reacting a gaseous mixture containing ethylene, carbon monoxide, and steam and thereby producing propionic acid the step of passing the gaseous mixture over a solid acidic oxide asa catalyst for the reaction.

4. In a process of reacting a gaseous mixture containing ethylene, carbon monoxide, and steam and thereby producing propionic acid the step of passing the gaseous mixture over tungstic oxide as a catalyst for the reaction.

5. In a process of reacting a gaseous mixture containing ethylene, carbon monoxide, and steam and thereby producing propionic acid the step of passing the gaseous mixture over a tungstic oxidemolybdic oxide catalyst.

6. In a process of reacting a gaseous mixture containing an olefine, carbon monoxide and steam, and thereby producing an aIiphaticcarboxylic acid, the step of passing a gaseous mixture consisting of propylene, carbon monoxide,

and steam over a solid acidic oxide as a catalyst for the reaction.

'7. In a process of reacting a gaseous mixture containing an olefine, carbon monoxide, and steam, and thereby producing an aliphatic carboxylic acid, the step which comprises passing a gaseous mixture consisting of butylene, carbon monoxide, and steam over a solid acidic oxide as a catalyst for the reaction. I 8. In a process of reacting a gaseousmixture containing an olefinic hydrocarbon, carbon monoxide, and steam, and thereby producing an aliphatic carboxylic acid, the step which comprises effecting the reaction in the presence of a solid acidic oxide as a catalyst for the reaction.

GILBERT 1B. CARPENTER. 

